librealsense2: only apply patch to ROS 2

Noetic uses an older version that doesn't need this patch.

distros/distro-overlay.nix

@@ -90,13 +90,9 @@ let
     });
 
     librealsense2 = rosSuper.librealsense2.overrideAttrs ({
-      buildInputs ? [], patches ? [], ...
+      buildInputs ? [], ...
     }: {
       buildInputs = buildInputs ++ [ self.glfw self.libGLU ];
-      patches = patches ++ [(self.fetchpatch {
-        url = "https://github.com/IntelRealSense/librealsense/commit/847b74d3dcade2842ba138f321474159315ab8c2.patch";
-        sha256 = "sha256-zaW8HG8rfsApI5S/3x+x9Fx8xhyTIPNn/fJVFtkmlEA=";
-      })];
     });
 
     libuvc-camera = rosSuper.libuvc-camera.overrideAttrs ({

distros/ros2-overlay.nix

@@ -42,7 +42,7 @@ rosSelf: rosSuper: with rosSelf.lib; {
   };
 
   # This is a newer version than the build system tries to download, but this
-  # version doesn't try run host platform binaries on the build platform.
+  # version doesn't try to run host platform binaries on the build platform.
   foonathan-memory-vendor = patchExternalProjectGit rosSuper.foonathan-memory-vendor {
     url = "https://github.com/foonathan/memory.git";
     fetchgitArgs = {
@@ -65,6 +65,18 @@ rosSelf: rosSuper: with rosSelf.lib; {
     nativeBuildInputs = nativeBuildInputs ++ [ self.buildPackages.cmake ];
   });
 
+  librealsense2 = rosSuper.librealsense2.overrideAttrs ({
+    patches ? [], ...
+  }: {
+    patches = patches ++ [
+      # Fix missing cstdint include
+      (self.fetchpatch {
+        url = "https://github.com/IntelRealSense/librealsense/commit/847b74d3dcade2842ba138f321474159315ab8c2.patch";
+        hash = "sha256-zaW8HG8rfsApI5S/3x+x9Fx8xhyTIPNn/fJVFtkmlEA=";
+      })
+    ];
+  });
+
   popf = rosSuper.popf.overrideAttrs ({
     nativeBuildInputs ? [], postPatch ? "", ...
   }: {